Silver core-shell

Fig. 11.12 Examples of highly sensitive SERS substrate, (a) SERS-active gold-silver core-shell nano-dumbbells (GSNDs) [85] and (b) shell-isolated-nanoparticle-enhanced Raman spectroscopy (SHINERS) [50]...

Figure 33 (a) Schematic representation of pseudorotaxane of dibenzylammonium ions and dibenzo-24-crown-8-ether. (b) Schematic representation of silica-silver core-shell aggregation from dibenzylammonium-functional silica 62 and crown-ether-functional AgNP 63. (c) TEM image of the cote-shell aggregates. Reproduced from Ryan, D. Nagle, L. Rtzmaurice, D. Nano Lett. 2004,4,573-575. ... 

Thermoplastic polymer polyphenylene sulfide (PPS)/BST composites were obtained with various BST contents. Particles were uniformly dispersed in PPS matrix using a twin-screw extruder, and composites with 70 wt% BST had a dielectric constant and dielectric loss of 13.5 and 0.0025, respectively, at 1 GHz [139]. Li et al. [140] embedded Bao.6Sro.4Ti03/silver core-shell nanoparticles into PVDF matrix. The silver-coated Bao.6Sro.4Ti03/PVDF nanocomposites showed 73% higher dielectric constant than composites of bare BST meanwhile, the dielectric loss was still low (less than 0.2) at 55 vol% filler content. 

Nischala K., Rao Tata N., and Hebalkar Neha. Silica-silver core-shell particles for antibacterial textile application. Colloids Surf. B Biointerfaces. 82 no. 1 (2011) 203-208. 

Extracts from Neem leaf broth have been used to synthesize gold, silver and bimetallic gold/silver core-shell nanoparticles [75]. In the individual nanoparticle... 

Bimetallic nanoparticles, either as alloys or as core-shell structures, exhibit unique electronic, optical and catalytic properties compared to pure metallic nanopartides [24]. Cu-Ag alloy nanoparticles were obtained through the simultaneous reduction of copper and silver ions again in aqueous starch matrix. The optical properties of these alloy nanopartides vary with their composition, which is seen from the digital photographs in Fig. 8. The formation of alloy was confirmed by single SP maxima which varied depending on the composition of the alloy. 

Anandan et al. [37] reported the sonochemical synthesis of gold-silver bimetallic nanoparticles with core-shell geometry by the sonochemical co-reduction of Au and... 

Fig. 7.4 (a) Carbon spheres loaded with silver nanoparticles at room temperature (b) carbon spheres loaded with palladium nanoparticles by refluxing (c) silver core of carbon spheres from encapsulation of silver nanoparticle seeds, (d) layered structure with an silver core, a platinum shell, and a carbon interlayer, formed by seeded encapsulation followed by the reflux method. 

Lu LH, Wang HS, Zhou YH, Xi SQ, Zhang HJ, Jiawen HBM, Zhao B (2002) Seed-mediated growth of large, monodisperse core-shell gold-silver nanoparticles with Ag-like optical properties. Chem Commun, pp 144-145... 

The dye radical, by reacting with a silver ion on the grain surface, could be responsible for the spectrally sensitized formation of surface image on the iridium doped grains and those of the (S+Au)-sensitized core/shell emulsions (Section IX.H). 

Xue et al. have explored the SPR excitation-mediated deposition of silver on gold nanoprisms that exhibit SPRs in the NIR, see Figure 11.56 [131]. With NIR excitation, core-shell nanoprisms with triangular gold cores and triangular silver shells are formed. In a control experiment, when the solution was irradiated with 550 nm light, only silver nanoprisms without gold cores are formed. These results show that it is the... 

Bimetallic nanomaterials Currently used monometallic SERS tags such as gold and silver NPs have a main drawback in that the metal surface is unprotected. The assays are therefore unreliable as components of the analyte can adsorb on the metal surface, leading to the possibility of replacing the label species. One way to overcome this problem is to encapsulate the metal particle/label molecule in a protective shell. Bimetallic nanostructures, with two different metals in a single particle, such as core-shell-type nanomaterials are gaining importance as Raman tags [1]. 

Two electric dipole SP resonances are observed for such composite particles, in agreement with the theory for the linear optical absorption from core-shell particles, see Figure 12. Furthermore, as the amount of silver in the shell of the particles is increased, the amplitude of the high energy SP resonances increases. However, it is clearly seen that the interband transitions are observed in tire linear optical photo-absorption spectroscopy of liquid suspensions of these gold core - silver shell particles but not observed on the corresponding SHG spectra. Tliis question of the role of the interband transitions is still open. 

There are a large number of inorganic NPs that can be potentially used in the biomedical field among them, metallic NPs (MNPs) such as gold, cobalt, iron oxide, core-shell silica/gold and more recently silver have been studied. In addition, during the last few years, biological applications of carbon nanoparticles... 

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